I'm going to take yet another moment here to point out what I've done when talking about the Merwin, Hulbert.
Parts for these reside in other folks' guns - and those folks are proud of them.
Gone are the days when one would see parted-out revolvers on the gun show tables in profusion - guys like Dave Chicoine and Bill English and many other collectors bought them long ago, before anyone thought that they might want to shoot these old DA revolvers at all, much less compete with them.
And in case no one noticed - pretty much all of the 'old' parts guys (the knowledgeable ones) are no longer seen at the shows, so if you do run across an accumulation of old parts, you can't expect to diddy-bop up to the 30-year-old owner and ask - 'Got any fairly rare mainsprings and un-buggered screws that are wildly undervalued?' and expect him to even have heard of what you're looking for.
'If' he can price something - he's using a copy of the 'Jack First' or 'Gunpartsco' catalog to assign a value.
Today, it's catch as catch can - and all you can really hope for is that 'you' can identify the rusted thing in that cigar box before the other guy does.
Good Hunting!
Scouts Out!